Rapid enzymatic urine screening test to detect bacteriuria in pregnancy

Objective: To determine the sensitivity, specificity, and positive and nega tive predictive values of an enzymatic urine screening test for diagnosing bacteriuria in pregnancy. Methods: Clean-catch midstream urine samples were collected from 383 women who had routine prenatal screening for bacteriuria. Sensitivity, specificit y, and positive and negative predictive values for each screening test (enz yme activity, nitrites or leukocytes on dipstick, and bacteria or pyuria on microscopic examination) were estimated using urine culture as the criteri on standard. Urine cultures were considered positive if they grew 10(4) col ony-forming units of a single uropathogen. Standard deviations used to calc ulate 95% confidence intervals were based on binomial distribution. A sampl e of 30 urine specimens was selected to evaluate interrater agreement using Cohen's kappa statistic. Results: Five of 383 samples were contaminated, leaving 378 samples for eva luation. Thirty of 43 specimens with positive urine culture had positive en zyme activity. Of 335 samples with no growth, 150 had negative enzyme activ ity. Sensitivity, specificity, and positive and negative predictive values for the Uriscreen enzymatic screening test (Bard Patient Care Division, Mur ray Hill, NJ) were 70%, 45%, 14%, and 92%, respectively. Sensitivity of the Uriscreen was lower than that of bacteria alone. Interrater agreement for Uriscreen testing was high among the three testers (K = .86). Conclusion: The Uriscreen enzymatic screening test had inadequate sensitivi ty for rapid screening for bacteriuria in pregnancy. (C) 2000 by The Americ an College of Obstetricians and Gynecologists.